Fingal County Manager David O'Connor claimed the low-cost DART spur would offer "little benefit" to the people of north Dublin, would not serve airport workers, would not be able to compete with buses and would result in fewer DART links to other stations.

His comments follow on the Irish Independent's recent disclosure that the €2.5bn Metro North project was to be shelved in favour of the DART plan.

Funding

The Government ordered Iarnrod Eireann to update the 1991 plan to build a 6.5km spur to the airport, from just beyond Clongriffin DART Station, with the cost estimated at €300m.

The move came amid concerns about funding Metro North which was to link St Stephen's Green to Swords via the airport.

In a report to councillors, Mr O'Connor said the Metro would help to develop north Dublin, lead to the creation of 25,000 jobs and reduce road traffic.

The DART, he claimed, would not help deliver any of the inward investment planned for Fingal, and DART customers would be "detrimentally affected" because trains would have to be taken off the Howth/Malahide lines to serve the airport.

"Dublin Airport accounts for around 20pc of the total patronage on Metro North, or six million passengers per year. Roughly half are workers in airport-related activities who live along the Metro North route. The DART spur would not serve any of these workers.''

And the DART spur was unlikely to be even competitive with the Aircoach service in terms of journey time, he warned.